From the freezer I put them in the bottom of the fridge for a day then the next day I take them while still in ziplock bag and place them atop my t5 coral lights on my marine tank for a few hours. The top of the fixture is always hot like a heating pad.

I used to soak them in hot water but I think I was doing something wrong bc it made them...structurally unsound especially in the belly region. Often I'd have the pleasure of cleaning up busted abdominal cavity goo/gut giblets after feeding. Also it made the house smell like rancid rat broth and I'd go thru a bunch of paper towels drying the rats off.